This invention relates to displacement transducers.
Most known displacement transducers are of an essentially analogue nature, and typical examples for measuring linear and rotary displacements respectively are linear and rotary potentiometers, in which the wiper of the potentiometer is moveable in dependence upon the displacement to be measured. However, when it is desired to process the output signals produced by such transducers digitally, e.g. when the transducers form part of a data logging system, it is necessary to provide an analogue-to-digital converter to convert the output signals into digital form. Some displacement transducers which produce a digital output signal are known, for example, linear displacement transducers based on the counting of Moiree fringes which move in dependence on the displacement to be measured and rotary displacement transducers employing Gray coded optical discs, but they tend to be both expensive and complex.
It is an object of the present invention to provide a simple and reliable displacement transducer, which can be relatively easily arranged to produce a digital output signal.